Centrifugal blowers



Oct. 14, 1958 P. scHLuMBoHM 2,356,117 I CENTRIFUGALBLOWERS Filed May 9, 195e I N VEN TOR.

United States Patent Oiiice 2,856,117 Patented Oct. 14, 1958 2,856,117 CENTRIFUGAL BLOWERS Peter Schlumbohm, New York, N. Y. Application May 9, 1956, Serial No. 583,742 1 Ctaim. (Cl. 230--127) The present invention refers to a centrifugal blower. More specifically it refers to a centrifugal blower which has an impeller which ejects air in a 360 arc in a welldened, jet-like beam. There are two such impellers of my own invention, one described in U. S. Patent 2,655,- 310, and the other described in my U. S. Patent 2,706,016.

The invention is illustrated in Figure 1 and Figure 2 of the accompanying drawings.

Figure 1 shows the apparatus partly in view and partly in vertical section.

Figure 2 is, on a reduced scale, a top view of Figure 1.

In the example illustrated in Figure l, the impeller 1 is of the type described in my U. S. Patent 2,706,016. Such an impeller comprises a plurality of porous discs, in this example live discs, which are superposed concentrically on an arbor 2 driven by the shaft of a motor 3. When rotating, a vacuum is created and maintained in the space between the discs. The air is, under the influence of this vacuum, sucked through the surface of the two outer discs and is ejected in a very dened jet of laminary ow characteristics at the periphery 4 of the discs.

My invention is based on the perception that an air jet of such characteristics makes it possible to construct a cowl 5 with a concentrical diiuser constriction 6 in the zone of the periphery 4 of said impeller 1.

I am aware that the combination of an impeller with a diffuser cowl is known in the art and my present invention is to construct an apparatus which is specifically practical as an air ventilator, and especially efficient with the impeller of my invention.

The following inventive steps are taken:

A. The air-collecting space 7 of the cowl 5 has a spout 8 which cooperates with the jet leaving the impeller to eject the collected air as a well-defined plane beam. In the known art a tubular spout was provided which would change the flow characteristics. In the case of pumping fluids, the known art shows even tubular pipes leaving the collecting zone at a right angle to the centrifugal plane.

ln this invention the spout is simply an opening in the wall of the cowl in the zone of its largest diameter and the opening is symmetrically arranged with reference to the centrifugal plane of the impeller. The opening extends to a fraction of the total circumference, for instance, to 60, as shown in Figure 2. Due to the centrifugal momentum of the collected air, the air leaves this opening spout 8 in a tangential direction but the air jet which leaves the impeller in this 60 section, has a steering and stabilizing influence on this beam of air. The edge of the opening 8 is molded with a lip 9. The lower lip 10 and the upper lip 11 run parallel to each other in the plane of the impeller. This also has a stabilizing effect on the air beam.

B. The inner walls 12, 13 of the cowl, which lead to the venturi restriction 6, are extended sufciently towards the center zone of the impeller to cooperate with the pumping effect of the outer discs 14, 15 of the impeller. As stated above, the air enters through these two outer discs into the impeller. In the case of my Patent 2,706,016, the air enters axially over the entire surface of these outer discs and one can formulate that the bound ary layer thus is sucked oi.

By this effect of the two outer discs 14, 15, the space walled by the walls 12, 13 benets from the air ow which brings air through the top openings 16 and bottom openings 17. This air flow assists the pumping eifect of the jet which enters from zone 4 of the impeller into the venturi constriction 6.

C. The cowl is made rotatable with reference to the axis of the impeller and the shaft of the motor. As shown in the drawing, the lower wall 12 of the cowl has a center section in the form of a hub cap 18 which glides on supports 19 connected to the motor 3. An inner hub cap 20 is fixated by spring-controlled bolts 21 to said supports 19. This arrangement makes it possible to rotate the outer hub cap 18 on the non-rotating inner hub cap 20 which works as an axle. By this rotation the direction of the air beam which leaves opening 8 can be varied.

Actually this structure can be so adjusted by adjusting the tension under which the inner hub cap 20 is attached by bolts 21 to the supports 19, that the outer hub cap 18 will glide freely and will rotate under the influence of the friction between the air and the inner surface of the walls of the housing 5. 1n other Words, the air is taking the cowl along in the sense of the rotation of the irnpeller. This arrangement produces a fan which will send out an air beam scanning the horizon like the light beam of a light house. Thus every corner of the room has temporarily the benet of the great depth of penetration of this air beam.

D. I found that metal cowls have a metallic din in response to `the vibrations of the motor, as well as of the air, and I found that it is highly advantageous to make the cowl from a rubber-containing material which does not respond to the high frequencies of sound.

l claim as my invention:

An air blower for circulating air in a room by sending a directional beam of air in a horizontal plane and continuously changing the direction of the beam while the blower is in operation, said blower comprising a stationary mounting base, a vertical drive shaft rotatably supported in` said base, said base having a pair of axially spaced supporting elements and a stationary connecting means therebetween, a horizontally arranged impeller secured to said shaft, a round housing coaxial with and enclosing said impeller and having gliding frictionai contact with said axially spaced supporting elements, said housing having a bottom wall, a peripheral wall and a top wall, said top wall having a central intake opening for said impeller, said peripheral wall having an opening therein comprising a fraction of its circumference amounting to approximately 60 degrees thereof, whereby as the centrifugal air leaves the housing in a tangential stream of flow the housing is rotated, the bottom wall of said housing protruding axially downwardly in the center zone thereof to form a hollow hub having a horizontal bottom wall portion between said axially spaced supporting elements and a peripheral vertical wall portion engaging one of said axially spaced supporting elements, the horizontal bottom wall having a central opening for said drive shaft and said stationary connecting means between said axially spaced supporting elements.

References Cited in the tile of this patent UNITED STATES PATENTS 86,320 Reichenbach et al. Ian. 26, 1869 174,813 Hargreaves Mar. 14, 1876 221,970 Miller Nov. 25, 1879 1,651,820 Hansen Dec. 6, 1927 1,778,046 Strobell Oct. 14, 1930 1,805,055 Stoetzel May 12, 1931 2,695,131 Price Nov. 23, 1954 2,706,016 Schlumbohm Apr. 12, 1955 FOREIGN PATENTS 963,924 France Jan. 18, 1950 

